Vyncolit and Sumitomo Bakelite highlight need for lightweighting powertrains in future electric vehicules

This was the key message delivered at the Lightweight Composite Solutions Conference organized by thermoset plastics professionals Vyncolit and Sumitomo Bakelite and held in Gent, Belgium. 

The automotive industry is on the cusp of some changes. Increasingly stringent regulations on carbon dioxide emissions are driving a move away from vehicles with conventional internal combustion engines to those with hybrid and fully electric powertrains. For example, in Europe, the fleet average emissions to be achieved by all new cars in 2021 is 95 grams of CO2 per kilometre. By 2025, this could be reduced further to 75 grams of CO2 per kilometre. The average emissions level of a new car sold in 2016 was 118.1 grams of CO2 per kilometre.

With the powertrain accounting for 32% of an electric vehicle’s weight, reducing this figure will be key in enabling these vehicles to travel further on a single charge and allowing smaller and cheaper batteries to be used.

The managing director of Vyncolit NV, Pieter Vanderstraeten, told the conference delegates: “All OEMs, have a lot of work to do in the next six to seven years. Lightweighting will be key in hitting these targets, regardless of the drivetrains employed. For electric vehicles, there are few standard technologies and limited means for the true mass production of electric motors. The need for regenerative technologies, small city cars and autonomous vehicles will change the requirements of braking technologies. All of these present opportunities for lightweight composite solutions.” 

Nissan’s General Manager of planning group, powertrain technology and prototype development department, Kimio Nishimura, outlined the OEM’s mid-term plan “M.O.V.E to 2022” to accelerate the electrification of its vehicles in order to hit the CO2 targets. He highlighted the need for compact, efficient and powerful motors, and heat-resistant, thermally conductive and low-permittivity materials for their construction.

Sumitomo Bakelite has developed a broad portfolio of materials and processing expertise that enable its partners to not only reduce the weight of their powertrain parts in comparison with metal solutions, but also save money through the opportunities plastics present for integrating many functions into a single component.

For example, Fraunhofer ICT’s Lars-Fredrik Berg talked delegates through the DEmiL project, the aim of which is to develop a direct-cooled electric motor with an integrated lightweight housing that delivers power on a consistent basis. A highly-filled, low-viscosity epoxy from Sumitomo Bakelite is used to overmould the motor’s stator. Channels are formed during this transfer moulding process that help to cool the active materials, helping to produce a motor with a very high weight-specific power output. 

In internal combustion engines too, there is still a significant scope for lightweighting using composites, thereby lowering fuel consumption and CO2 emissions. Group leader for composite materials at Robert Bosch, Gerrit Hülder, outlined the company’s work replacing aluminium fuel pumps with those made from plastics. Not only did this switch of materials lead to a weight saving of 40%, it also cut costs by 30% through a reduction in part count. 

Further still, Vyncolit NV’s Chief Innovation and Technology Officer Hendrik De Keyser told delegates that the use of phenolic resin for the manufacture of brake pads can slash the weight of the brake systems in a car by 1kg.